Tambellini was given a weak team when he started his reign as general manager, and he did very little to fix that. The team has depth at forward, but they need more of a veteran presence. That's how younger players learn how to be successful. With Eric Belanger injured, the only veteran forwards they have in the lineup are team captain Shawn Horcoff and long-time Oiler Ryan Smyth. If the Oilers are going to get any better, they need to bring in a few more veteran forwards.
The Oilers are also very weak on defense. They have a solid top-four, featuring Justin Schultz, Nick Schultz (no relation), Ryan Whitney, and Ladislav Smid, but the bottom two defensemen pairing leaves much to be desired. Look at the top teams in the league for example. Teams like Boston, Vancouver, and Chicago have three pairs of defenseman that give their team the stability they need in order to be successful. Edmonton simply needs more depth on defense.
Perhaps Edmonton's biggest problem is their goaltending. For the past few seasons, we have expected Devan Dubnyk to finally emerge as a top goaltender. With now-backup Nikolai Khabibulin's career in decline, Dubnyk was given the starting role and he has done very little to prove why he deserves it. Neither Dubnyk or Khabibulin give Edmonton the chance to be successful every night, but Tambellini refused to budge on his expectations of his goaltenders. The only way Edmonton is going to fix their team is by bringing in a top goaltender. The combination of a weak defense and terrible goaltending doesn't give the Oilers any chance at being an elite team, no matter how promising their offensive capabilities are.
Going forward, it will be very interesting to see how new general manager Craig MacTavish fixes the mess that Steve Tambellini made of the Oilers.